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44bda4b7d2
When a PCI device is detected, pdev->is_added is set to 1 and proc and sysfs entries are created. When the device is removed, pdev->is_added is checked for one and then device is detached with clearing of proc and sys entries and at end, pdev->is_added is set to 0. is_added and is_busmaster are bit fields in pci_dev structure sharing same memory location. A strange issue was observed with multiple removal and rescan of a PCIe NVMe device using sysfs commands where is_added flag was observed as zero instead of one while removing device and proc,sys entries are not cleared. This causes issue in later device addition with warning message "proc_dir_entry" already registered. Debugging revealed a race condition between the PCI core setting the is_added bit in pci_bus_add_device() and the NVMe driver reset work-queue setting the is_busmaster bit in pci_set_master(). As these fields are not handled atomically, that clears the is_added bit. Move the is_added bit to a separate private flag variable and use atomic functions to set and retrieve the device addition state. This avoids the race because is_added no longer shares a memory location with is_busmaster. Link: https://bugzilla.kernel.org/show_bug.cgi?id=200283 Signed-off-by: Hari Vyas <hari.vyas@broadcom.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Lukas Wunner <lukas@wunner.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> |
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| .. | ||
| cmm.c | ||
| dlpar.c | ||
| dtl.c | ||
| eeh_pseries.c | ||
| event_sources.c | ||
| firmware.c | ||
| hotplug-cpu.c | ||
| hotplug-memory.c | ||
| hvCall_inst.c | ||
| hvCall.S | ||
| hvconsole.c | ||
| hvcserver.c | ||
| ibmebus.c | ||
| io_event_irq.c | ||
| iommu.c | ||
| Kconfig | ||
| kexec.c | ||
| lpar.c | ||
| lparcfg.c | ||
| Makefile | ||
| mobility.c | ||
| msi.c | ||
| nvram.c | ||
| of_helpers.c | ||
| of_helpers.h | ||
| offline_states.h | ||
| pci_dlpar.c | ||
| pci.c | ||
| power.c | ||
| pseries_energy.c | ||
| pseries.h | ||
| ras.c | ||
| reconfig.c | ||
| rng.c | ||
| scanlog.c | ||
| setup.c | ||
| smp.c | ||
| suspend.c | ||
| vio.c | ||